Show limited formatting buttons on short description field editor

I assume the original intent was to display a limited number of formatting buttons on the product short description field. However, since `quicktags` is specified twice in the `$settings` array, we get the WordPress default set of buttons. This commit fixes that problem and also reduces the number of formatting buttons in the TinyMCE editor to match.
Merge pull request #3490 from emzo/patch-1

Show limited formatting buttons on short description field editor